Infineon Technologies Ag

Bernhard Endres

Klemens Pruegl

Jürgen Förster

Andreas STRAßER

A magnetoresistive sensor includes a sensing element and a stress inducing layer. The sensing element has a layer stack that includes a reference layer having a fixed reference magnetization aligned with a magnetization axis; a magnetic free layer having a magnetically free magnetization, wherein the magnetically free magnetization is variable in a presence of an external magnetic field; and a non-magnetic layer arranged between the reference layer and the magnetic free layer. The stress inducing layer is coupled to the layer stack and is configured to apply a force to the layer stack to induce a mechanical stress in the layer stack along a mechanical stress axis such that the magnetization axis is aligned parallel with the mechanical stress axis or perpendicular with the mechanical stress axis.

Inducing mechanical stress in magnetoresistive sensing element to align magnetization axis of reference layer system in preferred direction for improved sensor performance

A magnetic sensor system includes a magnetoresistive sensor comprising a magnetic free layer having a sensing plane and a magnetically-free magnetization arranged within the sensing plane, where the magnetically-free magnetization is variable in a presence of an in-plane magnetic field that is aligned with the sensing plane; and a ferromagnetic disc having a magnetic vortex in a ground state, wherein the magnetic vortex is configured to react to an out-of-plane magnetic field and generate a stray field in response to the out-of-plane magnetic field being applied to the ferromagnetic disc. The stray field has an in-plane magnetic field component that is proportional to the out-of-plane magnetic field. The magnetic free layer is configured to receive the in-plane magnetic field component of the stray field. The magnetically-free magnetization is configured to change based on the in-plane magnetic field component of the stray field.

Magnetic field sensor system with magnetic vortex used for b-field redirection for out-of-plane magnetic field

A tunnel magnetoresistance (TMR) sensing element includes a layer stack having a tantalum-nitride (TaN) layer; a reference layer system; a magnetic free layer having a magnetically free magnetization; and a tunnel barrier layer arranged between the reference layer system and the magnetic free layer. The reference layer system includes a pinned layer having a fixed pinned magnetization; a reference layer having a having a fixed reference magnetization; a coupling interlayer arranged between the pinned layer and the reference layer; and a natural antiferromagnetic (NAF) layer comprising iridium-manganese (IrMn), wherein the NAF layer is formed in direct contact with the TaN layer, wherein the NAF layer is configured to hold the fixed pinned magnetization in a first magnetic orientation and hold the fixed reference magnetization in a second magnetic orientation, and wherein the direct contact of the NAF layer with the TaN layer increases a blocking temperature of the NAF layer.

Iridium-manganese-based tunnel magnetoresistance sensing element with tantalum-nitride buffer layer for increased thermal stability

In some implementations, a magnetic sensor may apply an electrical signal across a tunnel barrier layer of a tunnel magnetoresistive (TMR) sensing element. The electrical signal may have a first signal level during a first time period and a second signal level during a second time period. The second signal level may be different from the first signal level. The magnetic sensor may generate an offset-corrected sensor signal based on a sensor signal that results from applying the electrical signal across the tunnel barrier layer of the TMR sensing element.

Offset correction in a voltage controlled magnetoresistive sensor

Exemplary embodiments are directed to magnetoresistive sensors and corresponding fabrication methods for magnetoresistive sensors. One example of a magnetoresistive sensor includes a layer stack, wherein the layer stack includes a reference layer having a fixed reference magnetization, wherein the fixed reference magnetization has a first magnetic orientation. The layer stack furthermore includes a magnetically free system of a plurality of layers, wherein the magnetically free system has a magnetically free magnetization, wherein the magnetically free magnetization is variable in the presence of an external magnetic field, and wherein the magnetically free magnetization has a second magnetic orientation in a ground state. The magnetically free system has two ferromagnetic layers and an interlayer, wherein the interlayer is arranged between the two ferromagnetic layers and includes magnesium oxide. The layer stack furthermore includes a barrier layer, which is arranged between the reference layer and the magnetically free system and includes magnesium oxide.

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Nabburg, Germany

Bernhard Endres